Pyrenochaeta lycopersici genome assembly showed interesting feature related to its lifestyle and interaction with the host

Pyrenochaeta lycopersici is a soil-borne pathogen that causes corky root rot disease in tomato (Solanum lycopersicum) and other Solanaceous crops, reducing fruit yields by up to 75%. De novo assembly of the P. lycopersici genome was based on Illumina sequencing and the functional characterization of the draft sequence by integrating RNA-Seq data was followed by an in-depth analysis of the virulence mechanisms and potential pathogenicity effectors encoded by this pathogen. We assembled a 54.9Mb P. lycopersici draft genome and annotated approximately 17,000 genes. The P. lycopersici genome is closely related to hemibiotrophs and necrotrophs, in agreement with the phenotypic characteristics of the fungus and its lifestyle. P. lycopersici genome reveals a significative expansion of specific genes families related both to pathogenesis and to reproduction mechanisms, including those responsible for plant cell wall degradation, nutrient absorption and fungicide detoxification. We also observed a significant expansion of the gene families associated with heterokaryon incompatibility (HI), which represents an important mechanism for this imperfect fungus for increasing genetic variability. The assembly constitutes an important resource to understand the molecular bases of corky root rot and more in general to enrich current knowledge of plant-pathogen interaction mechanisms.